The Reconquista River (Spanish, Río Reconquista[1]) is a small river in the province of Buenos Aires, Argentina. Together with the Riachuelo, it is one of the most contaminated watercourses in the country.
The Reconquista is part of the Río de la Plata basin. It originates in Marcos Paz, Buenos Aires Province, and flows across 18 municipalities, emptying into the Luján River. Its drainage basin has an area of 1,670 square kilometres (640 sq mi) and is populated by around 4 million people.
The river carries about 33 percent of the total pollution drained by the estuary of the Río de la Plata, taking into account both industrial and domestic waste. There are about 12,000 industries in its basin, 700 of which dump their waste into the watercourse without controls.
Studies have found nitrites, nitrates, ester-phenols, PCB, and heavy metals. These pollutants can cause hepatitis, skin reactions, gastrointestinal problems and eye infections.